Knitting machines are often equipped with so-called latch needles, which have a slender needle body that on one end forms a shank, and the shank, on its free end, changes over into a hook. In the vicinity of the hook, a sawslot is provided, in which a pivotably supported latch is disposed. This latch can execute a pivoting motion, thereby opening or closing the yarn space of the hook. Such latch needles are known, for instance from Japanese Patent Disclosure JP 61-133586. This latch needle has a sawslot that extends continuously from the needle cheek to the needle back, and the latch is supported freely pivotably in this sawslot without hindrance. In the vicinity of the latch bearing, the latch has a blunt extension with a rounded tip.
From U.S. Pat. No. 1,163,296, a sawslot is also known whose latch can be moved via a slide provided on the needle. To that end, the latch has a recess on one end, and this recess is associated with the tip of the slide, and by means of it the latch can be pressed away from the hook or the needle back as needed.
Because of the slide protruding into the sawslot, the latch is only conditionally freely rotatable. It is possible to operate such needles only with cams that have an additional track for the slide.
From Japanese Patent Disclosure JP 8-60504, a latch needle with a sawslot that is open at the back and with a latch spring that cooperates with the latch is known. On its end toward the spring, the latch has a flattened face and a cam, in order to define two stable positions of the latch.
All the needles mentioned suffer soiling in operation, and as a consequence a mass composed of fiber residues, oil and dust, for instance, can collect in the sawslot. Such accumulations of dirt impair the function of a latch needle if they become excessive.